Myofibrillar protein degradation patterns and structural changes in skeletal muscle from electrically stimulated Bos taurus and Bos indicus crossbred cattle

Degradation of titin, nebulin, desmin and troponin-T, structural changes in nonstimulated (NS) and electrically stimulated (ES) bovine skeletal muscle and comparison of these changes in Angus x Jersey (AxJ) cattle (Bos taurus cross) with the changes in Brahman x Simmental (BxS) cattle (Bos indicus cross) were determined. Myofibrils for SDS-PAGE and Western blots and intact muscle samples for transmission electron microscopy were prepared at 0, 1, 3, 7, 14 and 28 days postmortem (PM). In SDS-PAGE, ES slightly accelerated the degradation of intact titin (T1 band), nebulin, desmin and troponin-T in AxJ samples. In Western blots of AxJ samples, ES enhanced T1 degradation, the appearance of a 38 kDa desmin degradation product and the accumulation of the 30 kDa polypeptide but had no detectable affect on nebulin degradation. Both SDS-PAGE and Western blots of BxS samples showed that ES had no effect on degradation of T1, nebulin, desmin and troponin-T but slightly enhanced the accumulation of the 30 kDa polypeptide. These four proteins were degraded faster in AxJ than in BxS samples. ES accelerated the appearance of wide I-band fractures and increased the frequency of narrow I-band fractures in all samples and of intermediate and wide I-band fractures through day 7 in AxJ samples. In BxS samples, ES accelerated the appearance and frequency of all three types of I-band fractures through 14 days PM. All three types of I-band fractures were seen sooner in NS AxJ than in NS BxS samples. The frequency of all types of I-band fractures was greater in all AxJ than in all BxS samples. Twice as many intermediate and wide I-band fractures were present at 3, 7, 14 and 28 days in AxJ as in BxS samples. Z-line degradation occurred but was unaffected by ES or by breed. In conclusion, ES slightly accelerated the degradation of titin, nebulin, desmin and troponin-T in AxJ samples only and accelerated the appearance of wide I-band fractures in AxJ samples. ES caused all three types of I-band fractures to appear sooner in BxS than in NS BxS samples

Myocardium-derived conditioned medium improves left ventricular function in rodent acute myocardial infarction

<p>Abstract</p> <p>Background</p> <p>We investigated whether myocardium-derived conditioned medium (MDCM) is effective in preserving left ventricular (LV) function in a rat acute myocardial infarction (AMI) model.</p> <p>Methods</p> <p>Adult male Sprague-Dawley (SD) rats (n = 36) randomized to receive either left coronary artery ligation (AMI induction) or thoracotomy only (sham procedure) were grouped as follows (n = 6 per group): Group I, II, and III were sham-controls treated by fresh medium, normal rat MDCM, and infarct-related MDCM, respectively. Group IV, V, and VI were AMI rats treated by fresh medium, normal MDCM, and infarct-related MDCM, respectively. Either 75 μL MDCM or fresh medium was administered into infarct myocardium, followed by intravenous injection (3 mL) at postoperative 1, 12, and 24 h.</p> <p>Results</p> <p>In vitro studies showed higher phosphorylated MMP-2 and MMP-9, but lower α-smooth muscle actin and collagen expressions in neonatal cardiac fibroblasts treated with MDCM compared with those in the cardiac fibroblasts treated with fresh medium (all p < 0.05). Sirius-red staining showed larger collagen deposition area in LV myocardium in Group IV than in other groups (all p < 0.05). Stromal cell-derived factor-1α and CXCR4 protein expressions were higher in Group VI than in other groups (all p < 0.05). The number of von Willebrand factor- and BrdU-positive cells and small vessels in LV myocardium as well as 90-day LV ejection fraction were higher, whereas oxidative stress was lower in Group VI than in Group IV and Group V (all p < 0.05).</p> <p>Conclusion</p> <p>MDCM therapy reduced cardiac fibrosis and oxidative stress, enhanced angiogenesis, and preserved 90-day LV function in a rat AMI model.</p

N-Glycosylation of Human R-Spondin 1 Is Required for Efficient Secretion and Stability but Not for Its Heparin Binding Ability

[[abstract]]R-spondin 1 (Rspo1) plays an essential role in stem cell biology by potentiating Wnt signaling activity. Despite the fact that Rspo1 holds therapeutic potential for a number of diseases, its biogenesis is not fully elucidated. All Rspo proteins feature two amino-terminal furin-like repeats, which are responsible for Wnt signal potentiation, and a thrombospondin type 1 (TSR1) domain that can provide affinity towards heparan sulfate proteoglycans. Using chemical inhibitors, deglycosylase and site-directed mutagenesis, we found that human Rspo1 and Rspo3 are both N-glycosylated at N137, a site near the C-terminus of the furin repeat 2 domain, and Rspo2 is N-glycosylated at N160, a position near the N-terminus of TSR1 domain. Elimination of N-glycosylation at these sites affects their accumulation in media but have no effect on the ability towards heparin. Introduction of the N-glycosylation site to Rspo2 mutant at the position homologous to N137 in Rspo1 restored full glycosylation and rescued the accumulation defect of nonglycosylated Rspo2 mutant in media. Similar effect can be observed in the N137 Rspo1 or Rspo3 mutant engineered with Rspo2 N-glycosylation site. The results highlight the importance of N-glycosylation at these two positions in efficient folding and secretion of Rspo family. Finally, we further showed that human Rspo1 is subjected to endoplasmic reticulum (ER) quality control in N-glycan-dependent manner. While N-glycan of Rspo1 plays a role in its intracellular stability, it had little effect on secreted Rspo1. Our findings provide evidence for the critical role of N-glycosylation in the biogenesis of Rspo1.[[notice]]補正完

Myofibrillar protein degradation patterns and structural changes in skeletal muscle from electrically stimulated Bos taurus and Bos indicus crossbred cattle

Degradation of titin, nebulin, desmin and troponin-T, structural changes in nonstimulated (NS) and electrically stimulated (ES) bovine skeletal muscle and comparison of these changes in Angus x Jersey (AxJ) cattle (Bos taurus cross) with the changes in Brahman x Simmental (BxS) cattle (Bos indicus cross) were determined. Myofibrils for SDS-PAGE and Western blots and intact muscle samples for transmission electron microscopy were prepared at 0, 1, 3, 7, 14 and 28 days postmortem (PM). In SDS-PAGE, ES slightly accelerated the degradation of intact titin (T1 band), nebulin, desmin and troponin-T in AxJ samples. In Western blots of AxJ samples, ES enhanced T1 degradation, the appearance of a 38 kDa desmin degradation product and the accumulation of the 30 kDa polypeptide but had no detectable affect on nebulin degradation. Both SDS-PAGE and Western blots of BxS samples showed that ES had no effect on degradation of T1, nebulin, desmin and troponin-T but slightly enhanced the accumulation of the 30 kDa polypeptide. These four proteins were degraded faster in AxJ than in BxS samples. ES accelerated the appearance of wide I-band fractures and increased the frequency of narrow I-band fractures in all samples and of intermediate and wide I-band fractures through day 7 in AxJ samples. In BxS samples, ES accelerated the appearance and frequency of all three types of I-band fractures through 14 days PM. All three types of I-band fractures were seen sooner in NS AxJ than in NS BxS samples. The frequency of all types of I-band fractures was greater in all AxJ than in all BxS samples. Twice as many intermediate and wide I-band fractures were present at 3, 7, 14 and 28 days in AxJ as in BxS samples. Z-line degradation occurred but was unaffected by ES or by breed. In conclusion, ES slightly accelerated the degradation of titin, nebulin, desmin and troponin-T in AxJ samples only and accelerated the appearance of wide I-band fractures in AxJ samples. ES caused all three types of I-band fractures to appear sooner in BxS than in NS BxS samples.</p

Lymphoepithelioma-Like Carcinoma of the Lung: An Unusual Case and Literature Review

We described a case of lymphoepithelioma-like carcinoma (LELC) of the lung of a 65-year-old man with initial symptoms of intermittent chest pain and mild shortness of breath for 2 weeks. A right-lung mass was noted on chest computed tomography (CT) scan and was proved histopathologically as LELC of lung after video-assisted thorascopic lobectomy. He was successfully treated with lobectomy with postoperative adjuvant chemotherapy and is alive without signs of recurrence for 36 months after the diagnosis. It is important for clinicians, pathologists, and radiologists to understand the clinical, pathological, and radiological presentations of this neoplasm to avoid improper clinical decision making and misdiagnosis

Pulmonary Hilar Tumor: An Unusual Presentation of Sclerosing Hemangioma

Pulmonary sclerosing hemangioma is an uncommon benign tumor of the lung; however, on rare occasions it can arise from the pulmonary hilar region. Herein, we report a 53-year-old female patient who presented with a round opacity in the right upper lung field on a radiograph. Chest computed tomography scanning revealed a 3.1 cm mass in the right pulmonary hilum. Thoracoscopic tumor excision was subsequently performed. On pathohistologic study, the tumor was well defined and composed of round stromal cells and surface cells arranged in a papillary, sclerotic, solid, and hemorrhagic pattern. In immunochemical study, the round cells were positive for thyroid transcription factor-1 (TTF-1) and epithelial membrane antigen (EMA) and negative for cytokeratin. The surface cells were positive for TTF-1, EMA, and cytokeratin. Therefore, a final diagnosis of sclerosing hemangioma was confirmed. In conclusion, pulmonary sclerosing hemangioma is uncommon and rare in the pulmonary hilar region. CT scanning is useful to determine its benignity, although imaging features are not specific for a definite differential diagnosis from other pulmonary tumors. Therefore, tissue diagnosis is usually necessary, and pulmonary sclerosing hemangioma should be listed in the differential diagnoses of pulmonary hilar tumors

Targeting Chondroitin Sulfate Reduces Invasiveness of Glioma Cells by Suppressing CD44 and Integrin &beta;1 Expression

Chondroitin sulfate (CS) is a major component of the extracellular matrix found to be abnormally accumulated in several types of cancer tissues. Previous studies have indicated that CS synthases and modification enzymes are frequently elevated in human gliomas and are associated with poor prognosis. However, the underlying mechanisms of CS in cancer progression and approaches for interrupting its functions in cancer cells remain largely unexplored. Here, we have found that CS was significantly enriched surrounding the vasculature in a subset of glioma tissues, which was akin to the perivascular niche for cancer-initiating cells. Silencing or overexpression of the major CS synthase, chondroitin sulfate synthase 1 (CHSY1), significantly regulated the glioma cell invasive phenotypes and modulated integrin expression. Furthermore, we identified CD44 as a crucial chondroitin sulfate proteoglycan (CSPG) that was modified by CHSY1 on glioma cells, and the suppression of CS formation on CD44 by silencing the CHSY1-inhibited interaction between CD44 and integrin &beta;1 on the adhesion complex. Moreover, we tested the CS-specific binding peptide, resulting in the suppression of glioma cell mobility in a fashion similar to that observed upon the silencing of CHSY1. In addition, the peptide demonstrated significant affinity to CD44, promoted CD44 degradation, and suppressed integrin &beta;1 expression in glioma cells. Overall, this study proposes a potential regulatory loop between CS, CD44, and integrin &beta;1 in glioma cells, and highlights the importance of CS in CD44 stability. Furthermore, the targeting of CS by specific binding peptides has potential as a novel therapeutic strategy for glioma

Color Stability and Staining Susceptibility of Direct Resin-Based Composites after Light-Activated In-Office Bleaching

This study evaluated color stability and staining susceptibility of five direct resin-based composites (RBCs) subjected to light-activated in-office bleaching with 40% hydrogen peroxide (HP). The test materials included 5 RBCs, which consisted of one nano-filled, one sub-micron, one bulk-filled, and two nano-hybrid RBC types. Ten disc-shaped specimens of each RBC were fabricated and divided into bleaching (BLE) and non-bleaching (CON) groups (n = 5 for each group). Specimens were then immersed in red wine solution over 4 h. A spectrophotometer was used to obtain Commission Internationale de l’Eclairage (CIE) L*a*b* parameters for each of the following periods tested: before bleaching (TBA), after bleaching (TBL), and after staining (TST). Color stability and staining susceptibility were evaluated using two metrics, CIEDE2000 color differences (ΔE00) and whiteness variations using the whiteness index (ΔWID). Data were analyzed using repeated measures two-way analysis of variance (ANOVA) (α = 0.05). Statistically significant and clinically unaccepted ΔE00 and ΔWID were observed for all tested specimens between TBA and TBL. The nano-hybrid type RBCs showed the highest discoloration among materials after bleaching treatment. The BLE group exhibited significantly higher ΔE00 and ΔWID than the CON group for all the tested RBCs between TBA and TST. The sub-micron type RBC showed the highest discoloration among materials after immersion in the red wine. Conclusion. The light-activated in-office bleaching with 40% HP’s influences on color and whiteness index were material-dependent. The use of bleaching treatment also increased the susceptibility to red wine for all RBCs